The invention relates to a receiver for various frequency bands. The receiver is suitable in particular for a car radio that can used all over the world for all of the frequencies that occur.
With receivers and in particular receivers in car radios, it should be possible to receive various frequency bands, such as long wave, medium wave, shortwave, or ultrashortwave. For reasons of cost, it is necessary to make do with only one oscillator and one unconnected peripheral of the oscillator for all of the frequency bands. If the receiver is to be usable worldwide, then particularly in the ultrashortwave range, hereinafter also referred as the FM range, problems arise with regard to synchronism, the signal-to-noise ratio, and the pull-in and lock-in performance, if the frequency bands are relatively far apart and cannot be achieved by means of an integral divisor, for instance a divisor by 2, 4, 6, and so forth. In the FM range, the reception frequency range in Europe is between 87.5 MHz and 108 MHz (CCIR band, for Comitxc3xa9 Consultatif International des Radiocommunications; International Consulting Committee for Radio Communications). Since in Europe as a rule a high-side oscillator is used, the resultant oscillator frequencies at an intermediate frequency of 10.7 MHz are from 98.2 MHz to 118.7 MHz. In Japan, the FM band is between 76 MHz and 90 MHz. The low-side oscillator used as a rule in Japan, again at an intermediate frequency of 10.7 MHz, must accordingly oscillate between 65.3 MHz and 79.3 MHz. The low-side variant is required in Japan, for reasons of mirror selection. If the receiver is to be usable for both the European and the Japanese FM band and is to have only a single oscillator, then the oscillator must be tunable between 65.3 MHz and 118.7 MHz. The variation here is as follows:
118.7 MHz: 65.3 MHz=1.82.
An oscillator with this kind of wide tuning range is not readily feasible.
It is accordingly an object of the invention to provide a receiver which overcomes the hereinafore-mentioned disadvantages of the heretofore-known methods and devices of this general type in such a way that it is suitable for various frequency bands and makes do with a single oscillator.
With the foregoing and other objects in view there is provided, in accordance with the invention, a receiver that can be used in various frequency bands that includes an oscillator for generating an oscillator signal at an oscillator frequency, and a frequency divider having an adjustable or settable real divisor value. The frequency divider is connected to receive the oscillator signal and to provide an output signal having a frequency of the oscillator frequency divided by the real divisor value. The frequency divider includes a multiplier having an adjustable or settable integral multiplier value, and a divider having an adjustable or settable integral divisor value. The multiplier is connected in series with the divider.
In accordance with an added feature of the invention, the frequency divider includes at least one additional multiplier having an integral multiplier value and at least one additional divider having an integral divider value. The at least one additional divider is connected in series with the at least one additional multiplier. As a result, a greater quantity of divisor values can be generated.
In accordance with an additional feature of the invention, the multiplier is a mixer.
In accordance with another feature of the invention, the first divider is a counter.
In accordance with a further feature of the invention, the oscillator is a voltage controlled oscillator.
In accordance with a further added feature of the invention, when the oscillator is operated at an oscillator frequency range of 97.7 MHz to 118.7 MHz, the integral divisor value is 1 and the integral multiplier value is 1.
In accordance with a further additional feature of the invention, when the oscillator is operated at an oscillator frequency range of 97.95 MHz to 120.45 MHz, the integral divisor value is 3 and the integral multiplier value is 2.
In accordance with another added feature of the invention, the oscillator is operated at an oscillator frequency range of 114.75 MHz to 127.05 MHz, the integral divisor value is 3 and the integral multiplier value is 2.
In accordance with another additional feature of the invention, when the oscillator is operated at an oscillator frequency range of 108.5 MHz to 109.82 MHz, the integral divisor value is 10 and the integral multiplier value is 1.
In accordance with a concomitant feature of the invention, the oscillator and the divider are configured for use in a radio.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a receiver for various frequency bands, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.